History and physical examination:
A two years old male toddler was transferred to our center from a small town in the province with history of sudden onset left hemiparesis and lowering of consciousness since morning of admission day. There were no history of seizure attack or trauma. Patient was admitted to our center with Glasgow Coma Scale (GCS) of 13, agitated and without appropriate cooperation. Vital signs were within normal range and no abnormality was seen in initial laboratory testing which was performed in referring hospital. Physical examination revealed left hemiparesis with muscle forces of 2/5 and 3/5 in left upper and lower limbs respectively in the Medical Research Council (MRC) scale. Muscle spasticity or hyperreflexia was not present but left plantar reflex was upward. All cranial nerves examinations were intact as far as patient cooperation allowed. Head circumference was within normal range. Fundoscopic examination was not possible and not performed due to patient agitation. Because, there were no history of seizure and patient hemiparesis did not improve over time, a possibility of post ictal tod’s paralysis was unlikely.
Patient was brought to us with a non-contrast CT scanning which showed a relatively large, round and well-defined lesion adjacent to frontal horn of right lateral ventricle and head of right caudate nucleus extending superiorly to centrum semiovale and anteriorly. Tumor was significantly compressing and displacing left frontal horn inferiorly and medially and midline shift of almost 1cm was also evident. Lesion had a heterogenous density with a hypodense compartment relative to brain parenchyma but hyperdense relative to CSF in favor of cystic lesion and a hyperdense part demonstrating acute hemorrhage. Peripheral segments of lesion were hyperdense in some parts and iso to hypodense in other parts. Significant vasogenic edema was also evident in the adjacent brain parenchyma. There was no sign of hydrocephalus (Figure 1 A-C).
Because of unavailability of emergent MRI at the time and the need to evaluate lesion enhancement and rule out potential vascular lesions, we performed an emergent contrast enhanced CT/CTA. Lesion did not show any vascular connections to the adjacent vasculature such as anterior cerebral artery or smaller branches nearby which somewhat relieved our concerns about vascular anomalies. Lesion showed a significant rim enhancement which was demonstrating enhancing wall of the cyst (Figure 1 D-F).
Management and surgical technique:
Given the clinical situation of patient, an urgent surgical management was performed. After administration of total intravenous general anesthesia, patient was positioned in neutral supine position with his head placed on a ring head holder and slight neck flexion with attention paid to not compromise venous drainage. Potential pressure points were carefully padded and warming blanket was used to avoid hypothermia during surgery (Figure 2 A, B).
After administration of prophylactic antibiotic (Cefalexin) and prophylactic antiepileptic (Phenytoin), a horse-shoe incision was made on right frontal region extending medially to midline and posteriorly to coronal suture. After subgaleal elevation of skin flap, a rectangular craniotomy was performed extending from 1cm anterior to coronal suture 3cm anteriorly and from approximately 1cm off midline 2cm laterally (Figure 2C). A U-shaped dural incision was made and dura was reflected medially. After identification of middle frontal gyrus, a small corticotomy and subsequent blunt dissection was performed through white matter fibers with a posterior, inferior and medial trajectory to reach tumor. Yasargil (Leyla) brain retractors were placed to maintain surgical access. Tumor had a thick purple capsule with adjacent yellowish gliotic tissue. Tumor capsule was friable and entered using suction and bipolar cautery. Hemorrhagic fluid content and blood clots mixed with necrotized tissue were suctioned. Tumor capsule was totally resected using suction and bipolar cautery under microscopic view till the gliotic tissue could be seen in entire periphery of surgical cavity. CSF egression from a small rent into right ventricle frontal horn was encountered during resection of deep medial parts of tumor capsule which was secured with a cotton patty to prevent blood backflow into ventricle. Meticulous hemostasis was achieved using oxidized regenerated cellulose and surgical site irrigation was done. Dura was sutured in a watertight fashion and bone flap was secured in place. Surgery duration was approximately two hours.
Patient was extubated immediately after emergence from anesthesia. Immediate post-op examination revealed complete consciousness without any significant changes in pre-operative motor status and with no surgically imposed new focal neurological deficit. Patient was admitted to pediatric ICU. On first post-operative day, there was considerable improvement in patient motor status with 3/5 and 4/5 muscle forces of left upper and lower extremities respectively. Agitation resolved and he had complete tolerance of oral feeding. Post-operative contrast enhanced MRI was performed on the day after surgery which demonstrated gross total resection with no signs of enhancing tumor or hemorrhage in the surgical cavity (Figure 3). After a 2-day care in pediatric ICU, patient passed another uneventful day in pediatric neurosurgery ward and was subsequently discharged from hospital with medication and physical therapy orders.
Patient was brought to us 4 days later with subgaleal CSF collection in the surgical site without any signs of infection or raised ICP. This was managed conservatively with intermittent application of compressive dressing at home and on subsequent follow-up visit 10 days later there were no signs of pseudomeningocele in place. Neurological status was significantly improved and patient was able to walk independently but there was still a 4/5 paresis in left upper hand. After 4 months follow up, there is no sign of tumor recurrence and patient performs well without significant complaint or neurological deficit.
Histopathological examination revealed a moderately cellular mixed glioneuronal neoplasm in a myxoid bachground forming numerous perivascular pseudorosettes. Tumor cells were round and monotonous with low mitotic rate. Necrosis, atypia and endothelial proliferation were all absent (Figure 4). Immunohistochemistry (IHC) staining was positive for vimentin, S100, synaptophysin (scattered cells) and NSE and negative for EMA and CK. Also, 3% of cells were positive for Ki-67. These findings were consistent with PGNT (WHO grade I).